Choosing and Fitting a Pack

 

 

A)  PACK FRAME SIZE

 

            To measure back length ;

 

 i) Locate the point on the spine that is at the same level as the crest of the hip bone. The crest is the point at which the hip bone can be felt at the side sticking out.

 

ii) Locate the 7th Cervical vertabrae. This is the first prominent vertabrae felt as a finger is run downward from the base of the skull.

 

iii) Stand relaxed, with hands at your sides, and have someone measure along the contours of the spine between the level of the hip crest and the 7th Cervical vertabrae. This measurement in inches corresponds to the following pack sizes;

 

              15          16         17          18         19          20         21          22         23          24

 

 

 

 

 

 

 

 

 

 

 

¬        Short          ®

 

¬         Tall            ®

 

 

¬      Regular        ®

 

 

 

                                                                       

This section does not apply to the packs that are available only in a single frame size

·         Sebring

·         Miura

·         Snoyo

·         Yoyo

 

Please note: The Bora 30 and Khamsin 38 are available in only 2 frame sizes (Regular and Tall). These have a single frame stay but do not have a structured hip belt and are therefore able to span a wider range of back lengths in a given frame size. These are not considered to be "fully suspended" packs.

 

All  Other  Packs

·         Bora 40                       Bora 70            Nozone

·         Khamsin 50                Bora 80                                               Borea

·         Bora 60                       Bora 90

·         Bora 65                       Bora 95

 

These are available in 3 different frame sizes. We have used the designations Short, Regular and Tall for these 3 sizes. Each model has published volumes for each given frame size. Quite often, a customer will select a frame size based on its stated volume (“I need the extra 200 cubic inches a Tall will give me”). It is important to choose the correct frame size for a given back length. Correct, comfortable fit cannot be achieved with the incorrect size. DO NOT CHOOSE A FRAME SIZE BASED ON STATED VOLUME. We consider our pack volume measurements to be conservative. If possible, try to see an example of the model you are interested in stuffed to it's capacity.

 

In some cases, a measurement may fall between 2 sizes (in the 1" overlap area between the sizes). In this case, a judgement must be made using a loaded pack with the frame stays adjusted. In almost all cases, it will be better to go with the smaller of the two sizes and then size and adjust the shoulder straps and hip belt appropriately. In the case of the B40, K50, Nozone and Borea where the shoulder straps are sewn directly to the main bag, careful sizing is necessary, as changing the straps is not an option. Choosing the larger of two sizes in question often results in the shoulder straps not making contact at the back of the shoulder, even with the frame stays properly adjusted (see Fig. 4b)

Check to ensure that the exit point of the shoulder straps is correct (see Fig. 4a) and that the load lifters are still angled downward to the shoulder straps to join the shoulder straps slightly to the front of the top of the shoulder  (Fig. 4a). On larger packs, the position of the occipital cavity can be used as a guide to correct size. On some of the smaller volume packs (e.g. Bora 40), the load lifter straps will not form an angle with the shoulder straps. On these packs, the load lifter straps perform a stabilizing function rather than a load transfer and stabilizing function. Shoulder straps and hip belts are interchangeable. A pack is normally supplied with the sizes of components and frame matched (small with small, etc.), but any combination can be set up or ordered by a dealer.

 

 

B)  HIP BELT

 

            The hip belt size is based on a measurement around the hips at a position 2" below the point at which you would measure waist size (or approximately around the hip crest). The measurements correspond to the following sizes (in inches);

 

 

         26     27    28    29     30    31     32    33    34     35    36    37    38     39    40     41    42     43

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

¬             S              ®

¬             M            ®

¬             L              ®

 

 

·         When the hipbelt is properly positioned (centered on the hip crest) and tightened, the ends of the pads should extend at least 3 inches past the hip crest. This is to ensure even weight distribution around the entire pelvic structure. It is not unusual to have a hipbelt fit so that there is very little extra webbing between each pad and the buckle. This is okay as long as the hipbelt is properly positioned and tensioned.

·         Two special fit considerations should be noted;

1) If trying on a pack for winter use, you should try bulkier clothing with the  hipbelt to ensure it still falls within the range of a proper fit.

2) If planning a long hike and you have not trained extensively for it, you may lose considerable weight during the hike, causing the hipbelt to become too large.

 

·         If in doubt, try another size of hipbelt and take into consideration all of the information you can think of. It is possible that 2 hipbelts may be needed, one for winter expedition use and one for summer use (only in exceptional cases).

 

CAREFUL MEASUREMENT IS AT BEST ONLY A GUIDE TO DETERMINE A STARTING POINT FOR THE FIT PROCESS

 

 

C)  SHOULDER STRAPS

 

            With the correct frame size established, the correct shoulder straps may be chosen. It is extremely important that the frame stays be correctly shaped first (see section on bending the frame stays). If the frame does not properly match the contours of the back, some space may exist at the top of the back between the frame and the back, even with the shoulder straps properly tightened. This can have 2 effects on the fit. First, the perception may be that the shoulder straps are the correct size when, in fact, they are too long. Second, when tensioning the shoulder straps, the pack gets deformed toward the back and an increased amount of tension is required to make the pack feel snug against the back. This tension pulls the shoulders backward and pain will be the result after only a short distance.

           

 

When properly fitted and installed, the shoulder straps should contour smoothly from their point of contact with the upper back to the front under the armpit. They should also be in contact throughout the entire length of the shoulder strap padding.

 

DO NOT TRY TO EVALUATE THE FIT OF THE SHOULDER STRAPS BY MEASURING THE DISTANCE BETWEEN THE TOP OF THE SHOULDER AND THE POINT OF CONTACT  BETWEEN THE SHOULDER STRAP WITH THE BACK. THIS MEASUREMENT CAN BE HIGHLY INDIVIDUAL.

 

 

·         The adjustment buckle at the lower end of the shoulder strap should be positioned roughly even with a line drawn downward from the center of the armpit.

 

·         If there is no further adjustment possible in the webbing strap attaching the lower part of the shoulder strap, a switch to a smaller size set of shoulder straps should be tried.

 

·         Heavily muscled men sometimes require a set of shoulder straps one size up from the main bag size. Use your judgement. Do not go up a size in the frame for the sake of the shoulder strap size.

 

As a final adjustment, the shoulder straps can be raised relative to the frame sheet approximately 2.5 inches, effectively lengthening the frame slightly (See Fig. 3 for attachment).

(APPLIES TO B60 to B95 ONLY)

i) Undo the Velcro tabs running from the bottom corners of the main back pad to behind the frame sheet (1)

ii) Undo the Velcro strip at the top of the lumbar pad and swing the lumbar pad downward. (2)

iii) Slide your hand palm upward underneath the moulded back pad and locate the bottom edge of the plastic sheet the shoulder straps are sewn to. (A)

            iv) Separate the Velcro securing this sheet to the soft loop side Velcro of the frame sheet.(A & C)

v) With your other hand, move the shoulder straps upward or downward as desired, ensuring they are positioned evenly and allow the Velcro to re-attach itself. (4)

·         The above procedure should be performed to achieve the correct, even contact of the shoulder straps along their entire length and should be considered especially if your back measurement fell into the overlap area between two sizes (smaller of the two sizes chosen).

 

The quality of this fit may be evaluated by slowly tensioning the load lifter straps and watching the effect on the shape of the shoulder strap curve (see Fig. 4a). The weight of the pack should slowly be lifted from the shoulder straps, effectively transferring it to the hip belt. If any kinking or other deformation of the shoulder strap exists behind the shoulder;

            i) Check to make sure the shoulder straps themselves are properly tensioned. There should only be a minimum of tension in the shoulder straps when the load lifters are operated as the purpose of the load lifters is to slightly lift the shoulder straps from the shoulders, not to bring the pack in against the back.  Load lifters will bring the pack a bit closer to the body and help snug it in to the back, but they should not be used to compensate for a poor frame stay fit. When tensioned, the load lifters will pull the shoulder straps smoothly away from the shoulders, transferring the load to the hip belt while maintaining stability of the upper part of the pack. When tensioning the load lifters, the shoulder straps themselves should be loosened very slightly.

            ii) If the shoulder straps are properly tensioned, and deformation still exists, re-insert the shoulder straps slightly into the frame sheet. Several small adjustments may be necessary to achieve the final, correct fit. It is possible that at this stage a switch to a smaller frame size may be necessary.

 


Figure 3- Component Attachment

 


A) Shoulder strap assembly                                          1) Velcro tabs to secure corners of back pad

B) Moulded back pad (sewn in place)              2) Lumbar pad swings down

C) Frame sheet (removable)                                         3) Pockets in back of hip belt for stays

D) Aluminum frame stay                                              4) Shoulder straps move up or down

E) Lumbar pad                                                              

 

ANY TENSION IN SHOULDER STRAPS OR LOAD LIFTER STRAPS ENDS UP BEING BALANCED BY MUSCULAR EFFORT SOMEWHERE IN THE SHOULDER AREA. MINIMUM TENSION IS REQUIRED FOR EACH STRAP TO DO ITS JOB IF THE PACK IS CORRECTLY ADJUSTED.

EXCESS TENSION=PAIN

 

            The ideal angle for the load lifter straps is 45 degrees. This angle minimizes the tension required in the strap to achieve the two functions of these straps (load transfer and stabilization). In practice however, an angle of 30 to 60 degrees is quite acceptable.

 

 

 Bending the Frame Stays

 

            THIS IS THE SINGLE MOST IMPORTANT ADJUSTMENT TO ACHIEVE A COMFORTABLE FIT. FINE TUNING OF THE OTHER ADJUSTMENTS IS FUTILE UNTIL THIS STEP IS PERFORMED CORRECTLY.

            A rudimentary curve is given to the stays at the factory. In practice, this curve does not fit many people well. The reason for this is that the curve of the frame stays must conform exactly to the person's back to achieve a good fit and every back is slightly different.

 

ACCESS TO FRAME STAYS

Miura, B30, B40, K38, K50, Snoyo, Borea, Nozone - Access is via a flap inside the main bag on                                                     

               the frame side. Separate the Velcro securing the flap to expose a piece of webbing

               covering the stay. Withdraw the stay from its sleeve. When replacing the stay, ensure that

               the protective webbing  is in place over the end of the stay.

            Bora 60 , 65, 70, 80, 90, 95 -  (refer to Fig. 3 - component attachment for steps 1, 2)

1) Access the frame stays by flipping the lumbar pad downward and sliding the hipbelt downward off the ends of the frame stays. The B90 and 95 have a protective piece of webbing covering the lower ends of the stays. Release the Velcro securing this webbing to the frame sheet to expose the stays.

2) Slide the frame stays from the pack. Keep their orientation correct by placing them alongside the pack.

 

BENDING THE FRAME STAYS

            Refer to Fig. 6 for steps 3 - 6

3)  Stand  relaxed, with hands at your sides and bent forward slightly at the waist in the same manner as when measuring.

4) Have a helper place the stay against the your back in the same position it would be within the pack when worn. For single stay packs, you must position the stay across the shoulder blade area to determine proper curve. This is because the backpad straddles the shoulder blades and the frame stay gives the backpad its shape. Note that on packs with 2 stays,  the stays are splayed outward at the top across the area of the shoulder blade. Try placing the frame stay in the pocket on the hipbelt and wearing the hipbelt. This will help establish more precisely the positioning to be used for bending. (remove hipbelt before bending). When doing this, make sure the hipbelt is settled on the hips properly before having your helper mark the stay position against your back.

5) Beginning at the bottom of the frame stay, have your helper bend it a bit at a time to match the contours of the your back. The upper portion of a leg makes a good anvil for bending. If using a form to aid bending, avoid placing your hands too far apart when bending. While making for easier bending, this will create very sharp bends rather than a smooth curve. Note that there is one sharp bend at the top of the stays on some larger packs. This is for occipital cavity clearance and may be emphasized slightly after the stay has been bent to the back shape. In some cases, the stay will take on a very dramatic "S" shape. This is normal and you have probably done the job correctly.

6) Bend the second stay (if applicable) to the same shape as the first. Placing both on a flat surface will help you see how your work is progressing.

7) Re-insert the frame stays into the pack. On packs with an occipital cavity, some difficulty may be experienced about 3" from the top of the stay pocket. Do not force it! Make sure that the pocket is flat, loosen the load lifter and gently wiggle the stay into position. Reposition the hipbelt and fasten all Velcro.

 

HINT:  When the desired curve is achieved in the lumbar area, try rocking the frame stay in the lumbar area of the person's back. Excessive curve of the frame stay will result in the creation of a fulcrum in this area, and when the shoulder straps are relaxed, the pack will tend to swing away from the upper back (undesirable). If the frame stay can be rocked (watch the upper end), back off on the curvature a bit at a time until the stay remains relatively stable.

 

 

 FIG.4  - Correct Shoulder Strap Fit

 

B

 

A

 

C

 

D

 
 


 


                                    A) Correct - smooth fit of shoulder strap (constant contact)

                                    B) Incorrect - Bunching or kinking behind shoulder caused by;

                                                        1) shoulder straps too long

                                                        2) frame size too large

                                                        3) shoulder straps raised on frame sheet too far

                                    C) Incorrect - Shoulder straps need to be raised slightly

                                    D) Incorrect - Shoulder straps too small for person - try next size up

           

 

                                   

 

 

 

Fig. 6 - Contours and Placement of Frame Stays

 


 


Correct Loading of a Pack

 


 

 


           

a) preferable for moderate terrain                  b) more stable for uneven terrain

 

 

·         Items with the greatest density should be placed as close to the frame of the pack as possible and above the lower compartment.

 

·         Items of lower density such as sleeping bags and spare clothing should be used to pad out the load and prevent shifting.

 

 

 

Women’s Packs vs. Men’s Packs

 

There is no difference in the main bag or it’s frame measurement between the womens and mens packs. The only thing that makes a pack a woman’s model is the components (hip belt and shoulder straps) fitted to it. There is also no difference in size measurement between a mens and womens hip belt. The difference is shown in Fig. 5. Most women require slightly more flare (angle at which the belt sits on the hips) , and, generally there is slightly less distance between the lower ribs and hips in women. Therefore, the womens hipbelt is slightly narrower than the mens to prevent pressure in the area of the lower ribs in shorter-waisted women and is thermoformed to have a greater angle over the hips. However, it is not true that all women require womens hip belts and shoulder straps. Final choice should be determined by fit and comfort. On all structured hipbelts (B40 through B95), fine tuning of the angle of flare is possible by adjusting the angle at which the 2” webbing exits the front of the padding (see Fig. 5). Tilting the webbing upward tensions the top of the hipbelt more, causing a flaring of the bottom of the belt. Conversely, tilting the webbing downward slightly will cause the hipbelt to take on a more straight appearance and could alleviate problems with pressure along the top of the belt.

                       

 

 

 

FIG. 5 - Hipbelt Differences and Angle Adjustment

 


 

 

 

 

 

 

 


The Parts of a Pack

 

 


 

 

 


1)      load lifter straps

2)      load distribution adjusters (gray strap-applies to B90, B95 only)

3)      load stabilizers

4)      sternum strap

5)      shoulder strap adjusters

6)      hipbelt buckle

7)      compression straps